Refrigerating apparatus



April 18, 1933. E. B. MALLORY 1,903,827

REFRIGERATING APPARATUS Filed Feb. 14, 1930 INVENTOR HISATTORNEYSPatented Apr. 18, 1933 I UNITED STATES IJPAITENT "OFFICE EDWARD B.MALIJOBY, OF TENAFLY, NEW JERSEY, ASSIGNOR TO THE CLIMAX ENGINEERINGCOMPANY, OF CLINTON, IOWA, A CORPORATION OF DELAWARE nnrnmnnnrmeAPPARATUS Application filed February 14, 1930. Serial No. 428,326.

This invention relatesto improvements in refrigerating apparatus and isherein illustrated as embodied in refrigerating apparatus of the sealedunit type, employing a compressor, condenser and evaporator. Theinvention has particularly to do with the matter of cooling the domecasing and the vanous parts of the mechanism contained therein, and alsothe cooling of the condenser and the compressed refrigerant containedwithin the condenser.

The invention relates to certain new'and useful arrangements of thevarious parts of the apparatus including the dome casing and itscontained mechanism, together with the condenser and also the structureof these associated "parts whereby an apparatus is provided having highefliciency, with provision for cooling the apparatus by natural currentsof air set up as convection currents created by the heat given up by theparts to be cooled to the air in contact or associated relationtherewith. I i v The embodiment of the invention herein illustratedpossesses the further advantage of being a compact unit of relativelysimple construction and one which may be readily and cheaplymanufactured, and further possesses the advantages whereby the variousparts may be easily made and readily and quickly assembled by a simpleand inexpem sive operation.

, air is brought into circulation and passed in contact "therewithtoremove and carry therefrom that amountof heat to be dissipated,requisite for the production of good and highly elficient performance inoperation.

Attempts have been made heretofore to cool devices of this character byassociating the condenser in surrounding relation to the dome andspaced. therefrom, with the provision for a set of fins supported on andin contact with the dome serving as the support for the condenser coil.

The applicant after various tests, has found that better results can beobtained if separate and independent cooling fins are provided for thedome and the condenser respectively with no, or as little as possible,mental connection between these heated parts. This type of constructionsubstantially eliminates the conveyance of heat .from the dome to thecondenser coils by conduction travel, and permits each to be cooledindependently of the other by the convection currents of the air.Apparatus of this construction constitutes the subject matter of the'applicants co-pending application, Serial No. 374,015, filed June 27th,1929. In

the old type of device where the coil surat least, of the heat of thedome, as well as its own heat. Of course, an eflicient operationrequires that the condenser coils be capable of dissipating suflicientheat to cause parts which not only improves the operatingcharacteristics of the refrigerating unit but readily adapts the: unitto adesign of pleasing appearance. The condenser is disposed below thelower confines'of the dome whereby to actually remove these parts fromany substantial heat transferrin relationship. It is found that there issu stantially no heat "transfer from the bottom of the casing byradiation, and by locating the condenser below the casing, it is out ofthe path of the heat rising from the dome and accordingly, is notrequired to dissipate any of the dome heat. Further the dome andcondenser are provided with independent and separate sets of coolingfins, which are removed from each- COD- tion is that separate andindependent bodies of cooling. air are supplied to the dome andcondenser respectively whereby each is cooled independently of the otherto the extent of the full cooling capacity of the air.

Air currents established by convection are of relatively low velocity ascompared with currents created by fans or similar means, consequently adistinct problem is presented in cooling by convection currents. Thecooling to a large extent, is directly proportional to the radiatingsurface but unless the apparatus is made of large awkward form,difiiculty has been encountered in providing the large fin area withoutmaking the air passages so small as to greatly retard the circulation.By placing the condenser with its fins below the casing, adequate spaceis provided for the fins of both the condenser and the dome withadequate space for circulating air.

This invention relates to refrigerating apparatus of the general typedescribed and claimed in a-pplicants copending application Serial No.428,324, filed February 14, 1930, but differs therefrom in that separateand independent air currents are rovided for cooling the casing and thecon enser respectively; all of which action maybe accomplished by meansof the construction hereinafter more fully described.

As above pointed out, the apparatus of this invention utilizes separateand distinct bodies of air for cooling the dome casing and the condenserrespectively, and in this respect, it is somewhat like the inventiondescribed and claimed in applicants copending application, Serial N 0.428,325, filed February 14, 1930. However, the present invention isparticularly characterized as one in which the air for cooling the domeis supplied from the bottom and passes upwardly through the space belowthe casing and up around the sides thereof.

Various other advantages not specifically mentioned are contemplated forthepresent invention, as will readily a pear to one skilled in the artfrom the 0 lowing detail description of an illustrative embodiment ofthe invention.

It is to be understood that the present disclosure is merelygiven bywayof example and is not to be considered as limiting the invention in anyrespect.

The scope of the invention'may be determined from an understanding ofthe present disclosure and an appreciation of the principlesincorporated therein and the advantages provided thereby.

Referring now to the drawing, itwill be noted that:

Figure 1 is an elevational view in crosssection, disclosing arefrigerating apparatus constructed in accordance-with the presentinvention; Figure 2 is a plan view partly, in cross section taken on theline 2-2 of Figure l and looking in the direction of the arrows;

Figure 3 is a fragmentary cross-sectional plan view disclosing amodified form of fin construction around the dome casing of the aparatus; 1

igure 4 is a fragmentary elevational view in cross-section of a modifiedform of condenser construction.

By referring to the drawing, it will be observed that the presentinvention. is disclosed as embodied in a refrigerating apparatuscomprising a casing 10 which ma be of any suitable construction andwhicis sealed and serves as a housing for the motor 11 and compressor 12.

The casing 10 in the present disclosure constitutes a receptacle in thehigh side of the system for receiving the compressed refrigeratingmedium. This casing isentirely sealed from the atmosphere and as itconstitutes the housing for the motor and compressor all possibilitiesof leaks are eliminated and the entire system is one which iscompletely.

sealed.

It will be noted that the casing 10 is of general dome constructionpryeferably of metal having an annular groove 13 at its lower edge.Immediately above the groove 13 is a depression 14 whlch is adapted toreceive the base plate 15, constituting the closing wall or bottom forthe casing as well as the supporting base for the enclosed motor andcompressorf The base plate is held by means of the ring 13 which fitswithin the groove 13 with the joint soldered, welded or otherwisesealed. Thesealing means for the compression casing is described andclaimed in the copending application of Robert L. Alexander and James R.McCallum, Serial No. 431,524 filed February 26, 1930.

Throughout the intermediate portion of the base plate 15, the machinedsurface 16' tor. The stator of the motor is mounted in propersurrounding relationship to the rotor by means of the upstandingbrackets 26 which may be of any suitable construction,

extending upwardly from the upper plate 19,

of the pump. This bracket can be formed of a plurality of independentparts attached to the plate 19 or as an annular support formedindependently and secured to the plate or'as an integral casting on theplate.

The above description is given for the purpose of illustrating thecompact and simple internal motor and pump mechanism, which may beemployed in the present apparatus. Further reference to the motor andcompressor construction and arrangement will I be omitted in thisapplication, as these features constitute the, subject matter of aninvention of Robert L. Alexander and James R. McCallum, described andclaimed in theirco-pending applications, Serial No. 476,736

filed August 21, 1930 and Serial No. 484,537,

filed September 26, 1930,and are only referred to here for the purposeof disclosing a complete assembly.

The discharge of the compressor is tnrough the opening 27, which isclosed by a leaf Valve 28-, directly into the atmosphere inside of thecasing 10. The outlet for the compressed gases is through the pipe 29,the end of which terminates at the upper portion of the casing and'whichextends downwardly and terminates ina coil 30, constituting thecondenser for the apparatus.-

By referring to the figures in the drawing, it will be noted thatthecasing is adapted to be mounted above the supporting surface for theapparatus by any suitable means, such as for instance, the resilientsupporting legs 31, so that adequate space is provided below the base ofthe casing inwhich-the condenser may be accommodated without surroundingthe casing. By employing the resilient legs "here disclosed, greaterquietness in operation is obtained which eliminates thev desirability ofmounting the motor and compressor construction on resilient supportswithin the casing. Although any suitable form of support may beutilized, the resilient support here shown comprises a series of piosts40,secured to the under sideiof the n base 15 of the casing and theopposed posts 41 carried by the base ring-42. The coil springs 43 aredisposed around and in engagement with the posts whereby they are heldin position and constitute the yielding support referred to. J Y

The supporting surface referred to may be the top of a refrigeratingcabinet 70, if it is desirable to mount the apparatus in this manner.

The present invention is not limited to the -7o specific details ofconstruction of the condenser; that is to say, whether the condenser beentirely outside the confines of the casing or not, provided, however,that the condenser is disposed so as to occupy space below the bottom ofthe casing, whereby it is removed from lateral heat transferringrelationship with the casing.

On this point, it may be pointed out that the heat transfer from thebottom of the S0 7 casing, by radiation, is relatively small and thatheat conveyed by convection currents, passes upwardly from the dome anddoes not come near the condenser. The condenser in the presentdisclosure is shown as composed of two concentrically arranged coils ofpipes but obviously any arran' ement of piping may be embodied ifesired. However, it may be pointed out that the form of, condenser andcondenser assembly disclosed in this application, have been found to behighly desirable and to present many advantages from the commercialstandpoint, as it may be easily manufactured and assembled as a separateunit and independ- L ently of the other apparatus, and be subsequentlymounted with the other apparatus by a simple and cheap operation.

.i By reference to the right hand portion of Figure 2, it will beobserved that the two coils of pipe 32 and 33 respectfully, have acorrugated metal separator 34, placed therebetween. This separator ismade up from metal which is relatively flexible so thatit may be easilyshaped to be inserted between the pipes in which position its naturalresilience tends to hold it in place and also assists in maintaining thecoils in proper position. While in this position, the separator is alsomaintained in intimate contact with the coils whereby it may receiveheat from the coils by conduction and serve as heat radiating finstherefor.

Additional fins 35 and'36 may be added vinside and outside of the coilswhich are here i shown as single bent strips constructed similarly tothe centrally disposed-separator 34. These fins are added for thepurpose of increasing the radiating surfaces and obviously may be of anysuitable/construction, such as for instance, any of the constructionsdisclosed in the applicants co-pending applications referred to. orstrips may be secured to the pipes by welding or other suitable means sothat the entire condenser may be made up and assembled as a unitindependently of the other construction.

Surrounding the outer surface of the condenser, a shroud or skirtportion 37 is pro- In any case, these fins 'vided, preferably secured bywelding or other suitable means, to the outer fins or strip 36. Thisshroud serves to enclose the condenser whereby the chimney effect isincreased and also serves to improve the appearance of the machine.

f For the purpose of cooling the dome, a

plurality of fins 45 are provided thereon, ex-

tending'radially and an enclosing shroud 46 is positioned around thefins as shown in Figure 1. This shroud provides enclosed chimneys withthe fin construction whereby an inbreased convection draft isestablished for cooling the dome casing. The shroud attached in anysuitable manner, that is to may be secured tothe ends of the fins bymeans of welding the inner surface thereof to projections 47, formed oncertain of the fins, or, it may be left unattached, that is to say,freely supported on the fins, whereby ready 'removability is provided.The removability of the shroud in some instances, 7

may prove desirable in order to facilitate cleaning of the fins forremoval of dust and dirt which accumulates thereon. It has been foundthatian accumulation of dust and dirt on the fins and dome surface, actsas a heat insulator and impairs the efliciency of the cooling action.

Depending from the lower edge of the shroud 46, is a. skirt portion 48which may be say, it may be supported from the shroud as shown, or byany other means, provided however, that it constitutes a partitionbetweenthe condenser and the inner column of air serving cool the domecasing and its This skirt is provided with an inclined portion 49 whicprojects over the condenser and serves as a deflector plate to directthe air rising from the condenser outwardly and away from the shroud anddome fins. In the present illustration, the skirt is attached by meansof the flange 49 having a-beading thereon which is snapped intoengagement with'and held by a similar flange 50 on the bottom of theshroud This form of connection permits the shroud to be readily removedas desired. The skirt 48 has a depending portion 51 which condenser andthrough the space below the dome casintgmd up around the sides of thedome and v 6 the modification shown in Figure 3,

48 may be formed of insulatin it will be observed that a slight modifiedform of dome fins are provided in that the fins are bent up from asingle strip of metal 60. In this case,the portions 61 thereof areattached to the dome casin which give a relatively large metal to metacontact for conveyance of heat to the fins by conduction. This form alsooffers a relatively large amount of metal area for exposure to thecooling drafts of air. In this form, several of the U shapefin membersdisposed in spaced relation around the dome, may be provided with a lug62 adapted to accommodate the screw 63, whereby the dome may beremovably secured to the fins.

By referring to Figure 4, it will be observed that a slight modifiedform of condenser is provided in that the inner set 35 of condenser finsis eliminated and the inner coil 32, of the condenser, is wrappeddirectly in contact with the depending skirt portion 51. In this case,the inner skirt portion 51 will serve as a radiating surface fordissipating some of the heat of the condenser.

By the construction of this invention, a central chimney is produced inthe upper portion of which the casing with its enclosed motor andcompressor is mounted so that heat of the casing induces a draft ofconvection currents upwardly for cooling the casing.

Cooling means, such as fins are provided on the casing for increasingthe heat radiating surface and assisting in the formation of convectiondrafts. Accordingly, it is not in all cases necessary to provide theenclosing shroudaround the casing and cooling fins hereinafterdescribed, and illustrated in the drawing, as the chimney efl'ect willbe pro- ;vided by the depending skirt in combination with the finssurrounding the dome.

This is particularly true for instance, with the type of fins shown inFigure 3 which may be used with or without the enclosing shroud. Thisform always guarantees an adequate supply of air to the dome which comesup'from the bottom from a region removed from the heated parts of theapparatus whereby to assure an adequate supply of cooled air. The airwhich reaches the dome, will not be drawn from any region which has beensubjected to the heat of the condenser or other parts.

To assure this condition, the skirt portion material whereby the air onthe inside 0 the skirt will be insulated from the air on the exteriorthereof. If insulating material is provided, 4

it will maintain to a further degree, a sep-- aration of the bodies ofair cooling the easing and condenser respectively, so that in neitherinstance, does one of these parts re ceive the heat of the other.

In the present disclosure, the air which enters beneath the apparatusfor cooling the casing and condenser, is drawn in underneath thecondenser and skirt and then passes upwardly under the influence of theconvection drafts, but obviously, any manner of supplying the air to thecondenser and central chimney may be provided, that is to say, may besupplied directly upwardly through the base in which case, the machinecan be mounted tightly on the supporting surface.

The present disclosure shows the skirt portion as extending inwardlywhereby the condenser is mounted in a manner to partially underlie thecooling fins of the dome casing. Whereas this formation makes for a morecompact structure and permits the mounting, of the condensersubstantially within the confines of the overall dimension of theapparatus and in this regard, produces a better appearing apparatus, itis conceivable that the shroud and skirt portion may be positioned in avertical plane with the condenser mounted on the exterior of the lowerportion thereof.

When the shroud and skirt are vertically disposed, the overhangingdeflector surface 49 will be eliminated, but additional deflectorsurfaces may or may not be added, as desired. The main principle of thepresent device, therefore, is that of providing a ChlInney which drawsair from below and in which is induced a cooling draft for cooling thedome and the fin radiating surfaces thereof and further providing acondenser, outside of said skirt or lower portion of the chimney wherebyit may be cooled by an independent upward draft of cooling air which isentirely separated and independent from the air in the chimney servingto cool the casing.

In the event an insulating material is used, for the skirt construction,all possibility of conveyance of heat from the condenser to the chimneyair is eliminated.

In operation it will be apparent that the dome becomes heated both bythe operation of the motor and compressor contained therein and the heatof the compression of the,

. lVith this in mind, it will appear that the" heat of the condenserwill establish a draft of convection air currents underneath the outershroud 37 and upwardly in contact with T the surfaces thereof and thenceoutwardly as developed by the surface 49 of the skirt. This provides afresh and independent body of air for cooling the condenser.

It will also appear that the heat of the dome and surrounding fins willestablish a draft of convection currents inside of the shroud whichdraws air inwardly from the bottom up through the column located'belowthe dome casing and inside of the depending skirt portion 51.

It is found that the draft established in the interior as induced by thedome heat, increases the draft of air under the apparatus and therebyaccelerates the draft of air supplied to the condenser.

Another important factor is that of providing the bottom of the casingspaced above usually large area, each having an abundance of free airsurrounding the same in cooling relationship and finally the dome andthe condenser with their respective cooling fins are each cooled byindependent bodies of fresh air.

In addition to the above advantages, the present invention provides aconstruction which is of compact, simple arrangement and one whichproduces a pleasing desirable appearance such that it might be mountedin plain view in instances where such mounting is desired.

The efficiency of an air cooled refrigerating machine is materiallyreduced by the collection of dirt and dust on the cooling surfaces as itforms a partial heat insulation to the,

action of the cooling currents. By providing radiating surfaces in theforms of fins, as herein illustrated, which are free from the coils ofthe condenser, greater access is provided for cleaning purposes and itwill therefore be apparent that the cooling surfaces may be readilycleaned and the initial high efiiciency of the machine easilymaintained.

It will, of course, be understood that the machine of this invention maybe mounted in any desired location, that is, entirely independently ofthe cabinet to be refrigerated or associated therewith, mounted on thetop of the cabinet or in any conveniently located compartment therefor.

I claim:

1. A refrigerating apparatus of the character described comprising amotor and compending extension.

acter described comprising a motor and compressor in a sealed casinghaving means for support ng said casing spaced above a supportingsurface, cooling fins on said casing and a depending shroud extendingdownwardly below said fins and a condenser mounted on the exterior ofsaid depending shroud.

4:. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having cooling fins on saidcasing and a shroud enclosing said fins and having a dependingextension, and a condenser supported outside of said de- 5. Arefrigerating apparatus'of the character described comprising a motorand compressor in a sealed casing having cooling fins on said casing,and a shroud depending below said fins and a condenser mounted ontheexterior of said depending shroud, said shroud being constructed andarranged to permit air to enter through the bottom thereof and passupwardly around the casing.

6. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having cooling fins on saidcasing, and a shroud depending below said fins and a condenser mountedon the exterior of said' depending shroud, said shroud terminating shortof the supporting surface for said apparatus whereby to leave a spacefor air to enter through the bottom thereof and pass upwardly around thecasin K A refrigerating apparatus of the character described comprisinga motor and com pressor in a sealed casing having means for supportingsaid casing spaced above a supporting surface, cooling and a depen gshroud extending downwardly below said fins 4 and a condenser mounted onthe exterior of said depending shroud, said shroud being constructed andarranged to permit air to enter through the bottom thereof and passupwardly around the casing.

8. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having means for supporting saidcasing spaced above a supporting surface, cooling fins on said casingand 9. depending shroud extending downwardly below said fins and. acondenser fins on said casing mounted on the exterior of said dependingshroud, said shroud terminating short 0 said supporting surface wherebyto permit air to enter through the bottom thereof and pass upwardlyaround the casing.

9. A refrigerating apparatus of the character described comprising amotor andfcompressor in a sealed casing having means for supporting saidcasing with a space therebeneat-h, a shroud supported in spaced relationsurrounding said casing having a depending portion extending below saidcasing and a condenser surrounding the exterior of said dependingportion.

10. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having means for supporting saidcasing with a space therebeneath, a shroud supported in spaced relation,

surrounding said casing having a depending portion extending below saidcasing and a condenser mounted on the exterior thereof and a deflectorportion extending between the lower end of said shroud and the upper.

end of said depending portion.

11. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having cooling fins on saidcasing with their outer edges collectively defining the side surface ofa truncated cone, and a truncated conical shroud surrounding said casingand fins and supported by contact with at least some of said fins, andmeans for removably securing said shroud to said fins. J 12. Arefrigerating apparatus comprising a motor and compressor in a sealedcasing and means supporting said casing with a space therebeneath, heatradiating means on said casing and a skirt, said skirt extending in- 1wardly from the bottom outer edges of said heat radiating means andthence downwardly, and a condenser supported on the exterior of saiddownwardly extending portion of said skirt. A

13. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed, casing having means supporting saidcasing with a. space therebeneath, fins on said casing and a skirtextending inwardl from the outer lower portion of said fins and thencedownwardly in relation to said casing and a condenser mountedsurrounding the outside of the downwardly extending portion of saidskirt.

' 14. A refrigerating apparatusof the character described comprismglamotor and compressorin a sealed casing aving means 'supporting saidcasing with a space therebeneath, fins on said casing and a shroudsurrounding said fins and a skirt extending inwardly from the outerlower portion of said shroud and thence downwardly and spaced from saidcasing and a condenser mounted on the outside of the downwardlyextending portion of said skirt.

15. A refrigerating apparatus of the character described comprising amotor and com- 5 pressor in a sealed casing having means supporting saidcasing with a space therebeneath, fins on said casing, and a skirtextending inwardly from the outer lower portion of said fins and thencedownwardly and spaced 10) from said casing and a condenser mounted onthe outside of the downwardly extending portion of said skirtand asecond shroud surrounding said condenser.

16. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having means supporting saidcasing with a space therebeneath, fins on said casing and a shroudsurrounding said fins and a skirt extending inwardly from the outerlower, portion of said shroud and thence downwardly, and spaced fromsaid casing and a condenser mounted on the outside of the downwardlyextending portion of said skirt, and'a second shroud surrounding saidcondenser.

17. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing, having means for supportingsaid casing, fins on said casing and a shroud surrounding said fins anda skirt detachably attached to the lower edge of said shroud and acondenser supported on said skirt.

18. A refrigerating apparatus of the character described comprising acompressor and a motor in a sealed casing, spring supports for saidcasing and a condenser earned by said casing and disposed about saidsupports.

19. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing, having resilient means forsupporting said casing, and fins on said casing and a depending skirtsupported by said casing through said fins and a condenser mounted onthe outside of said skirt.

20. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing, having resilient means forsupporting said casing. and fins on said casing and a shroud surroundingsaid fins and a skirt depending from said shroud and a condenser mountedon said skirt.

21. A refrigerating apparatus of the character described comprising amotor and compressor in-a sealed casing having cooling fins on saidcasing and a shroud depending below said fins and a condenser mounted onthe exterior of said depending shroud.

22. A refrigerating apparatus of the character described comprising amotor and compressor in a sealed casing having cooling fins on saidcasing and a shroud enclosin said fins and having a depending extension,and a condenser mounted on the exterior of-said depending extension.

23. A refrigerating apparatus of the character described, having incombination a shroud constituting a substantially vertical chimney, acasing having a motor and compressor therein, mounted in the upperportion of said chimney and spaced from the sides thereof whereby theheat of said casing will induce an upward draft of cooling airaroundsaid casing suflicient to cool the casing during the operation ofthe machine, and a condenser mounted on the outside of said chimney.

24. A refrigerating apparatus of the character described, having incombination means constituting a chimney, a casing having a motor andcompressor therein mounted in the upper portion of said chimney andspaced from the sides thereof whereby the heat of said casing willinduce an upward draft of cooling air around said casing and a condensermounted outside of the lower portion of said chimney below the plane ofthe bottom of said casing.

25. A refrigerating apparatus having in combination a motor andcompressor in a sealed casing, means for supporting said casing with aspace therebeneath, means constitutmg a chimney surrounding said casingand space below said caslng and a condenser around the outside of saidlast named means,

the portion of said last namedmeans adjacent said condenser being formedof heat insulating material.

26. A refrigerating apparatus of the char acter described, having incombination means constituting a chimney, a casing having a motor andcompressor therein mounted in the upper portion of said chimney andspaced from the sides thereof whereby the heat of said casing willinduce an upward draft of cooling air around said casing and a condensermounted outside of the lower portion of said chimney below the plane ofthe bottom of said casing, the portion of said chimney adjacent saidcondenser being formed of insulating material.

27. A refrigerating apparatus of the character described, having incombination means constituting a chimney, a casing having a motor andcompressor therein mounted in the upper port-ion of said chimney andspaced from the sides thereof whereby the heat of said casing willinduce an upward draft of cooling air around said casing and a condensermounted outside of the lower portion of said chimney below the plane ofthe bottom of said casing, the portion of said chimney between saidcondenser and the casing and fins being formed of insulating material.

In'testimony whereof I afiix my signature.

EDWARD B. MALLORY.

